Composite covers replace very heavy steel or concrete access covers in high traffic and high wheel load situations, with multiple benefits.

Fibrelite (Skipton, North Yorkshire, U.K. and Pawcatuck, Conn.) can now provide a lightweight alternative to traditionally-used heavy concrete and metal access or manhole covers for areas imposing particularly high wheel loads such as aircraft pavements, taxiways of civil airports and dockyards.

The benefit of using a retrofit system is that costly and time consuming installation is eliminated. There are no breakouts of existing structures and no curing time resetting structures into concrete. In critical high trafficked areas this is a major advantage.

"Having re-configured the internal fibreglass architecture we can meet the permanent set and test load requirements of BS EN 124, Class F900 (when tested in accordance with the Air BP test footprint)," explains David Holmes, Fibrelite's technical director and head of product development.

The request for Fibrelite to provide F900 heavy-duty trench covers initially came from a large dockyard in the southeast of England. Their work inspectors were exploring replacement options for extremely heavy and corroding steel covers that had been installed years earlier, so heavy that they required a crane and dedicated lifting equipment, which incurred a financial cost every time ships come into dock.

“These highly engineered composite trench covers have eliminated costly and time-consuming procedures, and they allow for a load rating of up to 90 tonnes. The associated increase in productivity and significant reduction in costs were huge benefits for the consulting engineers and customers alike” explains David Holmes.

These lightweight composite access covers can be used for a multitude of applications: from ports and dockyards, industrial facilities, airports, HGV loading areas and also power stations, for example. The Fibrelite manufacturing process uses multi-axial E-glass fiber and a specially formulated resin matrix. The basic principle of this methodology is to dissipate load in the most effective way possible. By using lighter materials, operational injuries are prevented; the worksite is made safer and easier for installation.